460. ACMELLA OLERACEA Compositae Nicholas Hind and Nicki Biggs Summary. The taxonomy, distribution and cultivation requirements of Acmella oleracea (L.) R.K. Jansen (Compositae: Heliantheae) are discussed; a full botanical description and illustrations are provided. The problems with common names and lay-taxonomists on the World Wide Web are highlighted and a pertinent warning over the use of this, and other similar plants, is provided. When this plant first arrived in the Herbarium, for naming, it caused some interest not least because of the striking appearance of the capitula but also because a number of staff knew of it from fieldwork in Africa, Malaysia, and South America. The Toothache plant Acmella oleracea (L.) R.K. Jansen is widely known and its popularity can be ascertained from a quick look at the www. One search engine produced 7500 results for simply inputting one of the common names of this species  Toothache plant though it threw up several spurious results with just the word toothache, or plant. The results ranged from offering seed, plants for sale or exchange, and a whole host of herbal and folk medicine sites with basic information on the species. Many of the web sites caused much amusement, mostly at the rather cringe-making attempts at synonymy, and to the production of some rather strange common names. The source of the plant illustrated was from material grown by Colegrave Seeds from Ball & Co. (Illinois), now known as PanAmerican Seed Co. It apparently originated from a South African stock where the plants are grown for food and medicinal use. The species is, however, widely available, if one searches hard enough, from several seed suppliers; plants are also available from some suppliers and as a novelty it is often recommended as edge planting in subtropical schemes. Acmella oleracea might not, at first sight, be an obvious relative of the Sunflower, but it is. As a member of the tribe Heliantheae, it has all of the necessary characters, except the obvious ray florets, common in such genera as Zinnia, Cosmos, Rudbeckia, Coreopsis, and Helianthus which are also members of the same tribe. Using a hand # Royal Botanic Gardens, Kew 2003. Published by Blackwell Publishing Ltd, 9600 Garsington Road, Oxford, OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA 31